Dialysis, hemofiltration, and other blood treatments that make use of microtubular filters have prolonged the lives of patients with acute or chronic renal insufficiency. In hemodialysis, for example, a semi-permeable membrane or filter is used to remove unwanted substances from the blood while adding desirable components by the process of diffusion across the filter. In Hemofiltration, electrolyte is drawn through a microporous membrane filter and replaced with properly balanced fluid. The principal dialyzer used in the United States is the hollow fiber or capillary dialyzer. In the hollow fiber or capillary dialyzer, membrane material is spun into fine capillaries and thousands of these capillaries are packed into bundles that are used in the filters for filtration. In such filters, blood flows through the capillaries while dialysate is circulated on the outside of the fiber bundle or electrolyte is directly drawn from the blood and replaced by replacement fluid.
Membranes or filters are used in may blood processes including hemofiltration and hemodialysis. Such treatments include: hemodiafiltration, apherisis, hemoconcentration, and hemo-ultrafiltration. One of the limitations on the capabilities of these systems is cost. The process of manufacturing filters is complex and slow, which keeps costs high for the disposable components such as filters. There is an on-going need for methods and devices for reducing the cost of manufacturing such consumables. The invention provides such a method as described hereon.